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By N. L. Wimmler

"INTRODUCTION The Southern Cross district in Deer Lodge County, Mont., has been chiefly a gold producer. Most of the production has come from gold-bearing hematite-limonite ores. Some of these ores were mined and shipped to smelters for use as flux in smelting copper ores. A magnetite deposit in the Pomeroy property, containing no gold or other economic nonferrous minerals, was mined from 1921 to 1923, the ore being shipped to smelters for flux.The iron-bearing deposits in the Southern Cross area were examined by Bureau of Nines engineers/ on June 28, 1943, and October 14, 1943. As a result, a Bureau exploration project was recommended; it was conducted during 1944. A magnetometer survey was first made of the magnetite-bearing area at and in the vicinity of the Pomeroy property. Exploration by diamond core drilling was then conducted within this area, and in the Southern Cross and Hold Fast properties. The cyanide tailings dump at the Hold Fast mill was sampled by auger drilling.This report presents the data obtained by the Bureau of Mines exploration."

Dec 1, 1946

By D. Harrington

"Coal—mine explosions are accidents that can and should be prevented. In former years hundreds of lives were lost each year in the United States as a result of such explosions, but after 1932 the numerous precautionary measures adopted had reduced their frequency and severity 75 percent or more until in 1940 several very disastrous explosions marred the good record. Unfortunately, both the number and severity of explosions seem to be tending to increase compared with the relatively good achievement from 1933 to 1940. The requisites for an explosion are ever present in all soft-coal and many hard-coal mines. A certain combination of circumstances, such as a flame or an arc in a cloud of dust or in a body of gas or both may start an explosion at any time. The fact that the frequency and severity of explosions were lowered for 6 or 7 years is no guarantee that such freedom from explosions will continue, as the bad record of 1940 has shown, and underground workers should feel honor bound to exercise the utmost care so that they will not help to bring about the circumstances that will cause an explosion.Although mine operators bear the main responsibility for preventing explosions, miners can do many things to help. As about 9 out of 10 explosions begin at a working face, it is largely within the power of workers to prevent them. All miners should do their part willingly and should not defend a fellow workman from punishment, even from discharge, for disobeying necessary rules, whose disregard may cause the death not only of the safety-rule breaker but also of many of his coworkers.When a miner is careless and is injured some other way than by an explosion he may be the only one to suffer, but if his carelessness causes an explosion he not only endangers his own life but also that of every other man in the mine and possibly the lives of persons outside the mine.Experiments have shown that ignition of as small a quantity as 150 cubic feet of an explosive mixture of methane and air under certain circumstances can start an explosion that will traverse an entire mine. Thus, ignition of an explosive mixture of gas 1 foot down from the roof and 13 feet back from the face of a 12-foot entry might cause a widespread explosion if the right quantity and kind of dust were present. Many persons have ignited much larger quantities of gas without being killed, but they survived only because dust, confinement, and other conditions were not exactly ""right."""

Nov 1, 1940

By Carl Fisher

A microseismic roof fall warning system was field tested in Western and Eastern coal mines in the United States to better define the capabilities and limitations of the microseismic method in predicting roof fall Microseismic event and energy type data were obtained and documented for twenty-three coal mine roof falls. Field test results indicate that both the microseismic event and energy methods, as applied in this development effort, have a high probability for successful application in a commercially practical roof fall warning system. Based on the results and experience obtained during field testing, a commercial prototype microseismic roof fall warning system was designed and constructed. Although it was the intent of the program to field test the commercial prototype system, delays in equipment fabrication and contract time limitations did not permit field testing.

Jan 1, 1980

By Oliver Bowles

In 1943 the Bureau of Mines began a review of trends in consumption and prices of the more important nonmetallic minerals. The first report covering building materials4/ appeared in December of that year. The present paper, which deals with chemical raw materials and fertilizers, is the second of the series. The 34 years from 1910 to 1943, for which statistics are presented herein, comprise periods of uneventful peace, unparalleled prosperity, industrial depression almost to the point of stagnation, and two wars of world proportions.

Jan 1, 1945

The combined production value of natural abrasives, which consist of tripoli, special silica stone, garnet, and emery, decreased in 1985. Shipments of processed tripoli increased slightly in quantity but decreased 6% in value, Production of garnet, an abundant iron-aluminum silicate, increased 24% in quantity and 20% in value. There was an 11% increase in the quantity and a 7% increase in the value of refined garnet shipped when compared with 1984 shipments, a new record high. Production of crude special silica stone decreased 10% in quantity and 14% in value, and shipments of finished special silica stone products decreased 85% in quantity and 68% in value. Both the quantity and value of special silica stone finished products sold or used were the lowest since 1981. Production of emery, an impure aluminum oxide, decreased 56% in quantity and 61 % in value of product mined and shipped. [ ]

Jan 1, 1987

By J. W. Thompson

OIL AND GAS AS MINERALS. Oil and gas within the ground are minerals and the fact that they have attributes not common to other minerals because of their fugitive nature or vagrant habit, and the disposition to percolate, and the possibility of their escape from beneath one part of the surface to another, does not remove them from the class of minerals. Texas Co. v. Daugherty (Texas), 176 Southwestern, 717, p. 719, May, 1915. OWNERSHIP OF TAILINGS-ABANDONMENT. A corporation engaged in milling- and the reduction of ores deposited the tailings therefrom upon a portion of its own land lying in a gulch through which water flows at times in great volumes and with great force' and notwithstanding all reasonable efforts by dams and otherwise to retain its tailings, the tailings eventually were forced upon the lands of an adjoining owner; these tailings were valuable and their retreatment, intended by the mill owner, profitable; and the fact that the tailings were so washed down upon the lands of the adjoining owner and permitted to accumulate and remain for some considerable time is not sufficient to show an abandonment on the part of the owner of the tailings, where it is clear that the owner had no intention of so doing, but on the contrary, always intended to conserve and retreat the tailings.

Jan 1, 1916

By William W. Adams

The quarrying and related industries of the United States improved their safety record in 1938 by reducing their accident-frequency rate to a lower acid more favorable position than it has occupied at any time except 1935 since comparable accident statistics became available in 1916. The rates for 1935 and 1938 were identical. The number of men employed in 1938, although smaller than in 1936 and 1937, was larger than in any other year since 1930. Volume of employment, as measured by the number of man-hours worked in the industry as a; whole, likewise was larger than in any year since 1930 except 1936 and 1937. Reports from operating companies to the Bureau of Mines, United States Department of the Interior, showed that 77,497 men were employed in 1938, a decrease of 6,597 compared with 1937. This figure represents the average number of employees for the period during which the quarries and plants were active during the year, which in 1938 averaged 223 workdays per employee compared with 241 in 1937. A total of 17.3 million man-days or 133.8 million man-hours of work was shown for the industry as a whole, which indicated a weighted average of 7.75 hours per man-shift. Reports for 1937 showed a total of 158.3 million man-hours for the entire industry and an average workday of 7.81 hours. Accidents resulted in the death of 82 employees, 5 more than in 1937, and in 5,027 nonfatal injuries involving disability for more than the remainder of the day on which the injuries were received. The number of nonfatal injuries was 1,321 less than in 1937. As the number of deaths and injuries was reduced more, proportionately, than man-hours of employment, the accident-frequency rate per million man-hours of work declined, the rate for 1938 being 38.19 compared with 40.59 for 1937. In other words, accident occurrence to the average employee was 6 percent more favorable in 1938 than in 1937 on the basis of actual number of accidents and actual number of man-hours worked during the 2 years.

Jan 1, 1940

By Edward Keller

The work covered by this report was undertaken at the request of Dr. J. A. Holmes, late Director of the Bureau of Mines, to whom the writer had been recommended by C. W. Goodale and E. P. Mathewson, of Butte and Anaconda, Mont. The director's offer was accepted for the honor it conferred and for the useful results that might be promulgated by the work in the technical field covered. The investigation was facilitated by permission to visit various works and sometimes by contributions of important definite information on a given subject. It is therefore with pleasure that acknowledgment of courtesies is made to the following corporations and gentlemen: Anaconda Copper Mining Co., Raritan Copper Works, Baltimore Copper Smelting & Rolling Co., United States Refining Co., American Smelting &, Refining Co., B. B. Thayer, A. C. Clark, A. L. Walker, William H. Peirce, E. A. Cappelen Smith, H. H. Alexander, F. C. Newton, S. Rolle, R. W. Deacon, N. W. Pierce, O. C. Martin, C. N. Sappington, James K. Thomson, W. G. Derby, and the assistants of the writer, K. W. McComas and W. L. Raup. In this report considerable space has been devoted to general and theoretical principles on the ground that under modern conditions the best results in any field of activity can be attained only with the a. id of an adequate knowledge of the best theories underlying the practice. The diffusion of such knowledge in the field of sampling metallic metallurgical materials appears to have been quite insufficient, and it is felt that when the principles involved are once thoroughly comprehended their universal application will be appreciated, so that it will make no difference whether pig iron or gold bullion is offered for test. It may further be noted that a discussion of the theories underlying practical methods is placed under the caption "Practical Sampling," with the idea that no one can be a practical sampler unless he is capable of analyzing his methods. No attempt has been made to advocate any one method, but it is hoped that the analyses of all of the methods in use will show where each may be correctly and safely applied. The fact that it is possible to demonstrate the theoretical correctness of several methods indicates the invalidity of the claim that any single one of them is the standard.

Jan 1, 1916

By E. D. Gardner

"Trolley lines used in connection with electric haulage in mines are a source of danger and many lives have been lost by men accidentally coming in contact with the wires. Usually the wires in metal mines are sufficiently guarded to prevent men from touching them with their person or by pieces of steel which they may be carrying or their shoulders, while walking along the level. However, it is difficult to guard effectively the wires at loading chutes along the haulage ways and in spite of safe guards, chute tappers have been electrocuted through loading bars accidentally touching the trolley line.To overcome this danger the Calumet & Arizona Mining Co., at Lowell, Arizona formely used a hinged V-shaped trough made of 1-inch by 6-inch lumber, that was dropped over the wire in front of the chute, when the cars were being loaded. This arrangement interfered with the easy operation of the chute, and a cut-out device for the trolley line was devised by W. R. Gibson, chief electrician for the company. This cut-out is efficient easily constructed and roes not interfere with the operations at the chutes or with the motors operating on the same level.When the cut-out is open the electric current is carried past the gap by an insulated wire on the opposite side of the drift. A hinged board drops down over the ends of the trolley guard when the slide is open and Prevents anything touching the live wires. About ninety of these cut-outs are now in use in the mine,The levels under the scopes are timbered with drift sets placed 5 feet apart, and the loading chutes take up the space between two sets. All trolley wires in. the company's mines are carried 6 feet above the rails and guarded by two 1/2 by 6-inch boards placed on either side of the wire."

May 1, 1921

By Charles Vaught, Kathleen M. Kowalski

Safety and health professionals from all sectors of industry recognize that training is a critical element of an effective safety and health program. A major concern in the mining industry is how to train both an aging workforce and the expected influx of new miners and mine managers as older workers retire. Thus, a review of some of the basic principles of adult learning may be helpful to mine trainers. This paper discusses the principles of adult learning based on research in education and psychology. It stresses the importance of taking a systems approach to training, focusing on the relationship between the environment and technology, and understanding how workers interact with both. The authors argue that the principles of adult learning and a systems approach are fundamental to the delivery of effective training in the mining industry. Examples of training programs developed by the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health are presented within two broad performance domains: routine and nonroutine skills. Basics of curriculum development are also briefly presented to provide the mine trainer with a template for program development.

Jan 1, 2002

By Gregory P. Cole, Peter G. Kovalchika, Rudy J. Matetic, Adam K. Smith

Previous studies conducted by the National Institute for Occupational Safety and Health (NIOSH) have shown that approximately 90% of coal miners and 49% of metal/nonmetal miners had a hearing impairment by age 501. Mine workers are exposed to additional noise levels underground due to the reflection of machine generated noise that would otherwise dissipate in an above ground setting. Determining the sound absorption coefficients is essential in modeling the sound field in an underground mining environment. Sound absorption is a measure of the amount of acoustic energy that strikes a surface and is absorbed, rather than reflected. The acoustic environment that mining machines operate in is a critical factor affecting the sound pressure level exposure for mining machine operators. Impedance tube testing is an inappropriate method for determining underground absorption coefficients due to the brittle composition of some of the materials such as coal and slate. Classic absorption coefficient estimation using T60 measurements will not work well in an underground environment because the theory assumes: a finite room, a diffuse field, and relatively uniform absorption. None of these assumptions are true in an open-ended mine entry. This paper will present a method using a ray-tracing technique to determine absorption coefficients for underground mines. Absorption coefficients are determined and presented for octave bands from 63 Hz to 8 kHz. The absorption coefficients will be essential for determining and predicting potential overexposure to machine operators in different mine environments.

By A. D. Hahn

The Federal Bureau of Mines examined ilmenite-bearing sands in southern Texas as part of a program to discover sources of supply for the domestic titanium industry. Deposits were examined from May 1956 through January 1959 in the outcrops of sandstone beds in the Jackson group of Eocene formations in Lee, Burleson, Fayette, and Starr Counties on the Gulf Coastal Plain; in alluvial valley fill in Brewster County in southwest Texas; in the sand beaches of Matagorda Peninsula and the Galveston, Padre, and Brazos Islands--part of the offshore chain of barrier islands along the Texas coast; and in unconsolidated sediments in Willacy County on the Rio Grande delta in the southeast Texas.

Jan 1, 1961

By C. G. Maier

Relatively infrequent use by metallurgists of the term "sponge chromium" as contrasted to more than occasional reference to "sponge iron" may be ascribed to the fact that the former material is not a commercial product, while the latter has been known and used, at least in one form (Swedish sponge iron), for several decades. It is doubtful whether a true sponge chromium ever has been prepared heretofore in the laboratory by more than one or two investigators. Nature presents a much. more difficult problem to the investigator endeavoring to make sponge chromium than pertains to the production of more easily reducible elements such as iron or nickel. Recent widespread interest among metallurgists in the possibilities of powder metallurgy is ample incentive to explore the feasibility of producing pure chromium metal in finely divided form. The shift in terminology of this statement from "sponge" to the "finely divided form" is deliberate in emphasis of distinction between terms that occasionally have been used loosely. It would seem desirable that a uniform usage descriptive of finely divided metals be adopted. While to some it might seem preferable that the terra "powdered" metal be reserved for a finely divided form produced by mechanical means, as, for example, chromium produced by the mechanical comminution of electrolytic sheets or flakes, current usage of the term "powder metallurgy' involves no distinction as to source type of material. It is usually accepted, however, that a sponge metal is one reduced from oxide or other combined form at temperatures below the melting point of metal or oxide so that the particles of metal are pseudomorphic, at least macroscopically, with the source material, and, in consequence of the loss of material without change of external shape of the particles necessarily have an open, porous, or "spongy" structure.

Jan 1, 1942

By A. F. Robertson

"INTRODUCTION This report is supplemental to R.I. 4178 and deals with the work accomplished between June 15, 1945, and September 7, 1945, on the Mitchell-Hodge mine, Grady mine, Albea and York property, and Cuzzort property.ACKNOWLEDGMENTSIn its program or exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurigcal Branch, O. C. Ralston, chief, analyzes samples and performs benefication tests.Acknowledgment is due Mitchell H. Kline, chief, Raleigh Division, Mining Branch; Abraham L. Fox, acting chief, Raleigh Division, Metallurgical Branch; and Rowe McCrae, district engineers, U.S. Bureau of Mines, Gainesville,"

Jan 1, 1946

By Radford B. Langston, John A. Marjerison, Graham C. Howell, Hendrik A. D. Kirsten

Probabilistic design is gaining wider acceptance in the rock engineering community since it allows more rigorous determination of risk relating to ground fall or excavation instability. Risk analysis can be conducted by various means, but the basis is formed by either objectively or subjectively determining probability of occurrence of an event. In the case of rock engineering, this event is either instability or excavation failure. Rock mass classification systems provide objective analysis of data collected on a typically subjective basis that also relate closely to excavation stability. A probabilistic analysis technique is presented that uses statistical distributions of rock mass and material properties, ground support fixture specifications, stress conditions, opening geometry, and ground support installation quality to more rigorously determine probability of failure for an underground opening and the subsequent risk to personnel.

Jan 5, 2007

By John Rusnak, Christopher Mark

Point load testing is used to determine rock strength indexes in geotechnical practice. The point load test apparatus and procedure enables economical testing of core or lump rock samples in either a field or laboratory setting. In order to estimate uniaxial compressive strength, index-to-strength conversion factors are used. These factors have been proposed by various researchers and are dependent upon rock type. This study involved the extensive load frame and point load testing of coal measure rocks in six states. More than 10,000individual test results, from 908 distinct rock units, were used in the study. Rock lithologies were classified into general categories and conversion factors were determined for each category. This allows for intact rock strength data to be made available through point load testing for numerical geotechnical analysis and empirical rock mass classification systems such as the Coal Mine Roof Rating (CMRR).

By James C. Cawley

This paper updates an earlier report by the authors that studied electrical injuries from 1992 to 1998. The previous information is expanded and supplemented with fatal and nonfatal injury rates and trends through 2002. Injury numbers and rates were used to compare and trend electrical injury experience for various groups and categories. This information allowed identification of at-risk groups that could most benefit from effective electrical safety interventions. The data presented in this paper are derived from the U.S. Labor Department?s Bureau of Labor Statistics? Census of Fatal Occupational Injuries, Survey of Occupational Illnesses and Injuries, and Current Population Survey. Between 1992 and 2002, 3378 workers died from on-the-job electrical injuries. Electricity remained the sixth leading cause of injury-related occupational death. From 1999 to 2002, 4.7% of all occupational deaths were caused by electricity, down from 5.2% in the 1992?1998 time period. The cause of death was listed as electrocution in 99.1% of fatal cases. Contact with overhead power lines was involved in 42% of all on-the-job electrical deaths. The construction industry accounted for 47% of all electrical deaths between 1992 and 2002 but showed overall improvement from 1995 to 2002 by reducing its electrical fatality rate from 2.2 to 1.5 per 100 000 workers. In addition, 46 598 workers were nonfatally injured by electricity. Contact with electric current of machine, tool, appliance, or light fixture and contact with wiring, transformers, or other electrical components accounted for 36% and 34% of nonfatal electrical injuries, respectively. Contact with underground buried power lines was involved with 1% of fatal injuries and 2% of nonfatal injuries. The research of the National Institute for Occupational Safety and Health aimed at evaluating commercially available overhead power line proximity warning alarms is described. This paper is expected to be the initial step for eventual development of a performance standard for such systems.

Jan 1, 2008

By Jeffrey M. Listak

The National Institute for Occupational Safety and Health (NIOSH) conducted field tests to evaluate the effectiveness of a wet head continuous mining machine for reducing dust exposure for continuous miner operators. Wet head technology delivers water via sprays to the continuous miner's cutter head as opposed to traditional standard sprays located on the boom and body of the mining machine. The sprays, positioned directly behind each bit on the cutter head, deliver water at the point of attack, serving to cool the bits during mining to reduce the potential for frictional ignitions. The sprays also flood the coal with water to potentially suppress dust generation. Dust surveys were conducted at several mines to evaluate the wet head's effectiveness to control respirable dust exposure at the continuous miner operator location and in the immediate return. Results show that the wet head miner improved air quality at both locations to varying degrees in some cases and not in others when compared to a continuous miner with a standard spray system.

Jan 1, 2010

This chapter presents proportionate mortality ratios (PMRs) derived from death certificate data in the National Occupational Mortality Surveillance (NOMS) database for the years 1986 through 1993. At the time this report was prepared, 1993 was the latest year for which data were available. Industry is classified under the 1980 U.S. Bureau of the Census classification system [Bureau of the Census 1982]; cause of death, under the International Classification of Diseases, Ninth Revision (ICD-9) [World Health Organization 1977]. A PMR of 100 indicates a mortality risk for a particular industry group that is similar to that for all industry groups combined. A PMR over 100 suggests a higher risk; a PMR under 100 suggests a lower risk. PMRs are subject to many factors that affect their reliability and validity and may not be comparable across populations with very different causes of death. An elevated PMR for a specified cause of death among an occupational or industry group may indicate a relationship between a work exposure and the cause of death specified. However, there are many limitations of PMRs as a measure of risk; they are most useful for generating hypotheses about exposure-disease relationships, which can then be tested in other studies. Selected PMRs are presented separately for males and females for coal mining, metal mining, nonmetallic mineral mining and quarrying (which includes nonmetal, stone, and sand and gravel), and for oil and gas extraction. All PMRs have been adjusted for age and race. In general, PMRs are presented only if the lower 95% confidence limit exceeded 100. If a PMR in an ICD-9 subcategory was above 100, however, the PMR for the larger category into which the subcategory falls is always presented and may be less than 100. PMRs can be expected to be elevated for conditions that have a high prevalence in particular occupational groups. PMRs showed elevated values for conditions known to affect miners, such as coal workers' pneumoconiosis, pneumoconiosis due to silica, tuberculosis, chronic pulmonary heart disease, and injuries. Additional findings of interest were- • An elevated PMR for myocardial infarction among male coal miners (table 2-1); • Elevated PMRs for neurologic disease in general and anterior horn cell disease, in particular among male metal miners (table 2-3); • An elevated PMR for rheumatic heart disease in male metal miners (table 2-3); • Elevated PMRs for malignant neoplasms of the digestive organs and peritoneum and for malignant neoplasms of the colon and rectum in female nonmetal miners (table 2-6); and • Elevated PMRs for non-A, non-B hepatitis and arteriosclerotic heart disease among male oil and gas workers (table 2-7).

Jan 5, 2000

By Yumi Nakashima, Setsuo Maeda

Vibration magnitude and frequency of the z-axis vehicle seat are time-variant, which are influenced by not only vehicle vibration characteristics themselves but also road surfaces, speeds and the human body. There is little in the current reporting about evaluating and analyzing automobile seat vibration that focuses on the time-variant. Yaguchi et al.1 has proposed a method to evaluate automobile seat vibration that is based on judgments using a subjective mental state. Their method focuses on the time-variant magnitude of the peak frequency on a power spectrum density. However, their method has no consideration of all the frequency contents of the discomfort, nor comparison between different peak frequency vibrations. Suzuki2 has emphasized that the vehicle vibration should be judged by a series of vibration stimuli to evaluate, because the vehicle vibration is time-variant, which isn’t a matter of the relationship between a single vibration stimulus and a subjective response. He clarified that the human sensation to the vehicle vibration discomfort changes every moment showing the relationship between the frequency-weighted r.m.s. acceleration calculated every 5 seconds and the category judgment to vehicle vibration discomfort every 5 seconds. However, his study doesn’t show what parameter connects to the subjective final judgment to vehicle vibration. Therefore, we applied the method similar to ISO100563 considering the time-variant to the vehicle seat z-axis vibration evaluation. The new method for the vehicle seat vibration considering the time-variant was examined on the hypothesis that the final subjective evaluation must be conducted from the judgment summarizing a series of vibration stimuli. Methods The vibration bench system, which reproduces the movement of a vehicle floor, was used for the experiment with the single-axis (vertical direction) four-post road simulator system, which is usually used for a car, as shown in Fig.1. The experiment was done on the right side of the vibration bench using the floor vibration which was 5.5 minutes, 0.822 m/sec2 (Wk) over the range 0.5-20Hz with 4 male subjects (age ave21.5, SD0.5, weight ave75kg, SD7.91kg, height ave166.8cm, SD5.2cm) and 4 suspension seats. As Fig.2 shows, subjects evaluated the degree of discomfort every 5 seconds to each seat vibration measuring the seat z-axis vibration acceleration. [ ]

Jan 6, 2006